Shaft-kiln.



A. & W. STEIGER.

SHAFT KILN.

APPLICATION FILED AUG.4. 1911.

1,287,505. Patented Dec. 10, 1918.

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A. & W. STEIGER. SHAFT K ILN.

APPLICATION FILED AUG.4. 19!].

1,287,505. Patented Dec. 10, 1918.

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ARNOLD STEIGER AND WILHELM STEIGER, 0F ZURICH, SWITZERLAND.

SHAFT-KILN.

Specification of Letters Patent.

Patented Dec. 10, 1918.

Application filed August 4, 1917. Serial No. 184,543.

To all whom it may concern:

Be it known that we, ARNOLD STEIGER and WLLHELM STEIGER, both beingcitizens of the Republic of Switzerland, and residents of Zurich,Switzerland, have invented certain new and useful Improvements in Shaft-Kilns; and we do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters or figures ofreference marked thereon, which form a part of this specification.

The present invention has reference to improvements in shaft kilns, andit relates more particularly to a rotatable bottom in shaft kilns forcalcining cement, lime, and similar substances.

It has already been proposed to use in lime kilns, gas producers, andkilns for treating non-sintering substances a worm-like or spiralmember, or an organ having spirally disposed turns in steppedarrangement. Such organs, which are preferably provided with largelateral crushing faces, are well adapted to handle relatively softmaterial, but they are not suitable for handling nonhomogeneoussintering substances. In the latter case it is most difficult to obtaina uniform operation, and a consequent even sinking of the material undertreatment.

The object of the present invention is to provide a rotary kiln bottom,which assures an uninterrupted uniform disposal of the sinteringmaterial, no matter what the direction of rotation of the bottom.

The rotatable kiln sole, according to our invention, is characterized bytwo sets of knife-like cutting edges, of which the one set operates inthe one direction of rotation and the other set in the oppositedirection of rotation of the bottom, and which cutting edges arearranged on a working (delivery) surface or facing extending from thecrusher-head surmounting the bottom to the latters outer rim of largestcircumference, and which extend crosswise of a spirally extendingdelivery or discharge edge forming the boundary of the working surface.The outer discharge edge, as well as the working surface, ascend fromthe bottom rim toward the central crusher-head.

The cutting edges are preferably raised somewhat relative to therespectively adjoining step of the working surface, and

there are further provided, for enhancing the action of the cuttingedges, slot-like recesses or interstices between the individual steps.The delivery edge as well as the working surface can be extended clearto the apex of the crusher-head, and the latter may be providedwith-knife edges and eccentrically disposed attacking edges.

' Our invention will best be understood, when described in connectionwith the accompanying drawings, in which- Figure 1 represents a verticalsection through the lower part of a running shaft kiln, provided with arotary bottom of our invention;

Fig. 2 shows a section on line AB of Fig. l;

Figs. 8 and 4 represent respectively a side elevation and a plan View ofa somewhat modified construction of rotary bottom, and

Figs. 5 and 6 show respectively similar view of still anothermodification.

In the lower discharge end of the shaft kiln l is arranged the bottom 2substantially cone-shaped, which is supported by the shaft 3 and issurmounted by the crusher-head l having a greater base angle than thebody 2 and, which serves to break-up the clinker and is formed somewhatlike a boring-head. The shaft 3 is operated in theone or the otherrotary direction by a driving gear 5, located below the kiln proper.

The bottom 2, which is provided with the peripherally dis osedextensions 6, has a discharge edge 7 spirally extending from the rim ofthe bottom toward its center and ascending from the bottom rim to thecrusher-head 4:. The bottom or body 2 is provided with substantiallyflat wedgeshaped sector like projections, each having an edge 7 and anedge 8 or 9, so that the projections are arranged step-wise in both aradial and a vertical direction in a single spiral. This edge 7 formsthe outer boundary line of a working surface or facing 15, and itcooperates with two sets of knife-like cutting edges 8 and 9respectively, which ex- Qtom 2, from where it then drops onto adownwardly directed annulus 10 of the kiln,

and is finally dumped down the chute 11 into a suitable conveyor, notspecifically shown here.

In this manner, on the bottom rotating in the indicated sense, we obtainan uninterrupted and uniform breaking-up and discharging of thesintering kiln contents. At the same time the cutting edges 8 will besharpened on the clinker mass, while the edge 9 efiects the'slicing ofthe clinker. On the bottom revolving in the sense of the arrow C, theedges 8 will cut the clinker, and the edge 9 will be whetted.

In order to enhance the action of the edges 8, there is provided aheadof each edge an interstice 12.

In the constructional modification according to Figs. 3 and a, the edge7 as well as the facing 15, extend clear to the top of the crusher-head,and there are provided at the top knife-edges 13 and eccentric attackingedges 14.

In the modification shown in Figs. 5 and 6, the interstices or slots 12are more deeply recessed and form grooves, whereby the operative surfaceis still further enlarged.

What we claim is:

1. In a shaft kiln, a rotary support for material consisting of asubstantially coneshaped head provided with substantially flat toppedprojections arranged in the form of a single spiral, said projectionshaving cutting edges adapted to cut when said head is rotated in eitherdirection.

2. In a shaft kiln, a rotary support for material, consisting of asubstantially coneshaped head provided with substantially flat-toppedprojections and arranged stepwise in both a vertical and peripheraldirection in a single spiral, said steps having cutting edges increasingin length with the increase in length of the radii of the spiral.

3. In a shaft kiln a rotary support for material, consisting of asubstantially coneshaped head provided with substantially fiat-toppedprojections and arranged stepwise in both a vertical and a peripheraldirection in a single spiral, each step having both a substantiallyradial and a substantially vertical cutting edge.

i. In shaft kiln a rotary support for material, consisting of asubstantially coneshaped head provided with substantially flattoppedprojections and arranged stepwise in both a vertical and a. peripheraldirection in a single spiral, each step having both a substantiallyradial and a substantially vertical cutting edge, some of said cuttingedges adapted to out. when said head is rotated in one direction and theother cutting edges adapted to cut when said head is rotated in theother direction.

5. In a kiln, a rotary support for material, consisting of asubstantially coneshaped head provided with substantially flat-toppedprojections spaced apart and arranged in the form 01. a single spiral,said projections having cutting edges adapted to cutv when said head isrotated in either direction, and the apex of said head bein providedwith projections elongated lengt iwise of the cone axis.

6. In a kiln, a rotary support for material, consisting of asubstantially coneshaped head, surmounted by a crusher head and providedwith substantially fiat-topped projections spaced apart and arranged inthe form of a single spiral, said projections having cuttin edgesadapted to cut when said head is rotated in either direction, and theapex of said head being provided with pro ections elon ated lengthwiseot the cone axis, and a downwardly inclined discharge member below saidhead.

7. In a kiln, av rotary support for material, consisting of asubstantially coneshaped head provided with wedge-shaped spiralsector-like projections spaced apart and arranged in the form of asingle spiral, said projections having cutting edges adapted to cut whensaid head is rotated in either direction, and the apex of said headbeing provided with projections elongated lengthwise of the cone axis.

8. In a shaft kiln, a rotary support for material, consisting of asubstantially concshaped head provided with substantially fiat-toppedprojections spaced apart and ar ranged in the form of a single spiral,said projections having cutting edges radially offset from one anotherand adapted to cut when said head is rotated in either direction, andthe apex of said head having a greater base angle than the body thereofand provided with projections elongated lengthwise of the cone axis.

In testimony that we claim the foregoing as our inventioinwehave signedour names.

ARNOLD STEIGER. WILHELM STEIGER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

